System and device for detecting ferrous metal



July 15, 1958 M. s. GOTTLIEB 2,843,821

SYSTEM AND DEVICE FOR DETECTING FERROUS METAL Filed April 4, 1955 51 I 5 MP .25 5e 33 ||||||ll i q 27 5 33 3 (32 INVENTOR. 37 35 35 I MORTON s. GOTTLJEB .36 ATTORNEYS.

United States Patent O SYSTEM AND DEVICE FOR DETECTING FERROUS METAL Application April 4, 1955, Serial No. 499,139

4 Claims. (Cl. 324-41) This invention 'relates in general to certain new and useful improvements in a system and device for detecting ferrous metal.

It is an important object of this invention to realize a device that may be readily utilized by every one with out any special instructions, and to realize a system in a device of this type for detecting ferrous metal that uses a simple and inexpensive, low voltage direct current power source such as a single flashlight battery that can be quickly and easily replaced. This type of detecting device is particularly adapted for use and play by children.

Another important object is realized by a toy device that is simple and durable in construction, economical to manufacture, and which can be readily used by small children in substantial simulation of Geiger counters used by adults.

An important objective is realized by a rocker arm that carries a magnet at one end and one contact of a control switch at the other end, the rocker arm being movable upon attraction of the magnet with ferrous metal to close the contacts of such switch so as to actuate an electromagnetic vibrator, and hence actuate an indicating means carried by the vibrator. Other important advantages and functional results are obtained by the mounting of an indicating element onthe armature of the vibrator, which permits the indicator to swing pivotally within predetermined limits to denote the presence of ferrous material in close proximity to the detecting magnet.

Still another important object is achieved by the provision of an earphone in the electrical circuit between the electromagnetic vibrator and power source which acts to emit an audible signal when the circuit is operatively closed by the rocker arm upon the attraction of the magnet to ferrous material.

The foregoing and numerous other objects of the invention will more clearly appear from the following detailed description of a preferred embodiment, particularly when considered in connection with the accompanying drawing, in which:

Fig. 1 is an end elevational view of the toy detecting device;

Fig. 2 is a side elevational view of the device shown in Fig. 1;

Fig. 3 is a top plan view of the device shown in Fig. 2;

Fig. 4 is a longitudinal cross sectional view as seen along line 4-4 of Fig. 3;

Fig. 5 is a view in cross section as seen along staggered line 5--5 of Fig. 4;

Fig. 6 is a view in cross section as seen along staggered line 6-6 of Fig. l, and

Fig. 7 is a diagrammatic view of the electrical circuit and system utilized in the detecting device.

Referring now by characters of reference to the drawing, and first to Figs. 1-6, the detecting device includes a housing having a top wall 10, a bottom Wall 11, side walls 12 and end Walls 13. A handle 14 is fastened to top wall 10, the device being of a size to permit children to lift and carry it easily and conveniently by the handle with one hand.

Secured to one side wall 12 (Fig. 6) by fastening elements 15 is a bracket 16 having a clip retainer portion 17 adapted to receive and hold a low voltage, direct current power source 20, such as a single flashlight battery. One end of the power source 20 engages a terminal 21, while the opposite end engages a bow spring 22 forming a part of bracket 16, the spring 22 constituting a. second terminal for power source 20.

Fastened to top wall 10 is an electromagnetic vibrator 23 having an actuating coil 24 and a vibrating armature 25. An electrical circuit operatively connects the vibrator 23 to the power source 20. Disposed in this circuit between vibrator 23 and power source 20 is a control switch which consists of a pair of separable contacts 26 and 27 (Fig. 4). One of the contacts 26 is fixed to top wall 10 of the housing. The other contact 27 is secured to and carried by one end 30 of a rocker arm 31. A pivot pin 32 carried by arm 31 is pivotally connected to side walls 12 of the housing. The othe end 33 of arm 31 is apertured to receive a link 34 adapted to hold a permanent magnet 35.

The front end wall 13 of the housing includes a project-- ing semi-circular portion 36 which cooperates with a.

semi-circular internal portion 37, as is shown in Figs. 4

and 6, to provide a well structure generally indicated.

at 40. The well structure 40 is open at the top 41 (Fig. 4) and at the bottom 42 to provide a passageway through therein.

The roclter arm 31 is carefully balanced by the pro-- vision of a counterweight 43 carried by end 30 so as to hold contacts 26 and 27 normally in spaced relation as is shown in Fig. 4, thus maintaining the electrical circuit in an open inoperative condition. The forward end' 33 of arm 31 will abut a portion 44 (Fig. 4) of the housing to determine the uppermost position of magnet 35, and to determine the normal balanced position of arm.

31. In such normal inoperative position, the magnet 35: is located in well structure 40 with its lower end disposed internally of the housing.

A pivot pin 45 is fastened to armature 25 of vibrator 23, and extends upwardly through top wall 10 of the housing. An indicating element 46 is loosely mounted on pin 45. Carried on top wall 10 is an indicator housing 47 which provides a chamber for element 46, the side walls 50 (Fig. 5) of indicator housing 47 serving as means to limit and determine the range of rotative movement of indicating element 46. It will appear obvious that as the pin 45 is vibrated by vibrator 23, the pin 45 will cause the indicating element 46 to swing back and forth between side walls 50.

Pivotally attached by pin 51 to top wall 10 of the housing is a control lever 52 which includes a depending arm 53, the lower end of arm 53 having an upwardly concave formation 54 that constitutes a cam. In the center position of control lever 52, the cam formation 54 engages the top of rocker arm 31, and serves to hold the contacts 26 and 27 of the control switch in spaced relation. When lever 52 is moved to either side of the center position, the cam formation 54 is operatively disengaged from arm 31, and hence permits the contacts 26 and 27 to be brought together to close the electrical circuit.

Referring to Fig. 7 which shows more clearly the electrical circuit and its particular connections, it appears that one terminal 21 of the power source or battery 20 is connected to fixed contact 26 by wire 55. The movable contact 27 is operatively connected by wire 56 to terminal 57 (Figs. 6 and 7) that normally engages arma- 3 ture 25. The other terminal 22 of power source 20 is connected to an earphone 60 by wire 61, the earphone being located externally of the housing and adapted to emit an audible signal when the circuit is closed and vibrator 23 is actuated. The earphone 60 is connected by wire 62 to vibrator coil 24 Which in turn is connected to the armature 25. Of course, it is understood that contacts 26 and 27 and earphone 60 may be connected on the same side or on opposite sides of the power source 20, or in other equivalent arrangements, all Within the scope of the present invention.

The operation of the system and device is believed fully apparent from the foregoing detailed description of the parts, but for completeness of disclosure it will be noted that when control lever 52 is moved to the off position in which cam formation 54 engages arm 31, the circuit is maintained in an open position regardless of whether or not ferrous material is within the magnetic field of magnet 35. To condition the system and device for operation, the control lever 52 is moved to an on position which disengages cam formation 54 from arm 31. Because of the careful balance of arm 31, the contacts 26 and 27 will be held normally in spaced relationship. When the device is moved over ferrous metal so as to place such metal in the magnetic field of magnet 35, the magnet 35 will move downwardly toward such metal. Whereupon, the rocker arm is pivotally moved so as to bring contacts 26 and 27 together, and hence operatively close the electrical circuit. The vibration 23 is then actuated by the energization of coil 24 to move armature 25 and pin 45, and hence cause a rapid swinging movement of indicating element 46 between the limits of side walls 50. Moreover, the actuation of vibrator 23 causes an audible signal to be emitted in earphone 60.

It should be understood that changes and modifications in the form, construction, arrangements and combination of the several parts of the toy detecting system and device may be made and'substituted for those herein shown and described without departing from the nature and principle of this invention.

I claim as my invention:

1. A system in a toy device for detecting ferrous metal including an electrical circuit comprising an electromagnetic vibrator having an armature, a power source operatively connected to said vibrator, an earphone operatively located between and connected to said power source and said vibrator, and a switch in the circuit between said power source and said vibrator, the switch having separate contacts normally held in spaced relation so as to maintain said circuit in an open condition, a rocker arm, a pivot means mounting said arm in said device, one of said contacts being carried by said arm at one side of said pivot means, a permanent magnet carried by said arm at the other side of said pivot means, a pivot pin carried by said armature, an indicating element loosely 4 mounted on said pin, the magnet being attracted to ferrous material to cause displacement of said arm and engagement of said contacts to close said circuit so as to actuate said vibrator and armature, whereby to emit an audible signal in said earphone, and to cause pivotal movement of said indicating element.

2. In a toy detecting device for ferrous metal, a housing, an electromagnetic vibrator having an armature, and a power source carried in said housing, an electrical circuit operatively connecting said vibrator and power source, a switch in said circuit betwen said power source and said vibrator, the switch consisting of separable contacts, a rocker arm pivotally mounted in said housing, one of said contacts being carried by one end of said arm, a permanent magnet carried by the other end of said arm, a pivot pin carried by said armature, an indicating element loosely pivotally mounted on said pin, means on said housing for limiting the pivotal movement of saidindicating element, the magnet causing movement of said arm to bring the contacts together to close the circuit and to actuate the vibrator, whereby to actuate said indicating element.

3. The combination and arrangement of elements as recited in claim 2, but further characterized by a control lever carried on said housing, the lever being movable to a position to engage said arm, whereby to retain said contacts in spaced relation to maintain said circuit in an open condition.

4. In a toy detecting device for ferrous metal, a housing, an electromagnetic vibrator and power source in said housing, an electrical circuit operatively connecting said vibrator and said power source, a switch in said circuit between said power source and said vibrator, the switch including a pair of separable contacts, an earphone operatively connected in said circuit and located externally of said housing, a rocker arm, pivot means for mounting said arm in said housing, one of said contacts being carried by said arm at one side of said pivot means, a magnet carried by said arm at the other side of said pivot means, a well structure in said housing, the magnet being located in said well structure, the magnet causing movement of said arm upon attraction to ferrous metal to close said contacts and to actuate said vibrator, whereby to emit an audible signal in said earphone.

References Cited in the file of this patent UNITED STATES PATENTS 1,778,655 Wyman Oct. 14, 1930 2,521,745 Pope Sept. 12, 1950 2,637,115 Watson May 5, 1953 2,670,457 Hartman et al. Feb. 23, 1954 2,762,970 Balduman Sept. 11, 1956 2,788,484 Deming Apr. 9, 1957 2,794,166 Ferdon et a1 May 23, 1957 

